Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the annotations, the description discloses important behavior: it returns medians of current published prices only, does not return individual listings, includes usage and one-time medians only where at least 3 listings publish them, and reports the group's 90-day price-index change. These details meaningfully tell the agent what to expect from the result.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the core purpose and then covers alternatives and invocation modes. It is dense but mostly earns its length; some clauses could be trimmed, but none are irrelevant.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the output schema exists, the description need not explain return values in full. It covers purpose, alternatives, thresholds, no-argument behavior, and scope limitations, so an agent has enough information to call it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The description adds value by clarifying that the no-argument case lists group IDs and that group_id can come from the group price league, supplementing the schema's references.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: it gives a broad group-wide fair price for a product group, defined as the median entry monthly price per buyer tier. It explicitly distinguishes itself from price_benchmark and search_providers, so an agent can identify its role without inspecting the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives explicit usage guidance: use this for a general price guide, use price_benchmark for checking a specific quote, and use search_providers for candidates. It also explains that calling with no arguments lists group IDs, covering the main invocation modes.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.